RAM as well. You won't be reusing any DDR2 memory sticks, and very few people have been willing to switch to DDR3 mobo/RAM due to the low performance to price benefits.
That alone tacks on $700 to your "upgrade" which may as well be a fresh new build.
I'm still sticking with Intel next generation over AMD, simply due to performance and OC adaptability. It's worth the price for a high end enthusiast rig.
If I want to do a cheaper build, I'll do one around an E8400 or E8500 and OC it to 4ghz on liquid with reused components.